Dic: put a brave face(front) on, put on a brave face, put on a good face

• Friends will see you are putting on a brave face and might assume you've got over your grief.
• Scientists are putting a good face on the troubles.
• They've had some bad luck, but they've put a brave face on their problems.
• She's very ill but she's putting a brave front on it. (= making people believe her illness does not worry her)

***

1. If you put a brave face on a bad situation or put on a brave face, you try not to show how disappointed or upset you are about the situation.
   In American English you can also say put on a good face.
2. to behave in a way that makes people think you are happy when you are not.

.... Cobuild, Cambridge Idioms